Fixing Methods

Module 5: Fixing Methods

Dot & Dab (Dry Adhesive Fixing)

A popular method for attaching plasterboard directly to masonry walls using adhesive.

1. Surface Preparation
✔ Clean the Wall – Remove dust, loose mortar, or old plaster for better adhesion.
✔ Check for Damp – Do not use dot & dab on wet walls (use moisture-resistant board if needed).
✔ Prime if Necessary – Some porous surfaces (e.g., aerated blocks) may need a bonding agent.

2. Mixing and Applying Adhesive
✔ Use Gypsum-Based Adhesive (e.g., ThistleBond or similar).
✔ Mixing Ratio – Follow manufacturer instructions (usually powder + water to a thick paste).
✔ Application Pattern –

• Apply large adhesive dabs (~50-75mm diameter) in vertical rows, 300mm apart.

• Add perimeter beads for extra support.

• Total adhesive coverage should be ~15-20% of the board area.

3. Board Positioning and Alignment
✔ Lift & Press – Position the board onto the adhesive and press firmly.
✔ Check with a Spirit Level – Ensure vertical and horizontal alignment.
✔ Adjust Before Setting – Slide into place within 5-10 minutes before adhesive hardens.
✔ Temporary Support – Use timber battens or props to hold boards in place if needed.

Pro Tip:

• Leave a 10mm gap at the floor to prevent moisture wicking.

Metal Framing Systems

Used for constructing lightweight partitions and ceilings.

1. Installing Metal Stud Partitions
✔ Layout the Frame – Mark floor and ceiling tracks first, ensuring they are plumb.
✔ Secure the Tracks – Fix to floor/ceiling with screws or plugs.
✔ Insert Studs – Cut to height and slot into tracks, spacing 400-600mm apart.
✔ Check for Plumb & Square – Use a laser level for accuracy.

2. Fixing Plasterboard to Metal Frames
✔ Screw Selection – Use 25mm drywall screws (fine thread for metal).
✔ Screw Spacing –

• 150mm along edges

• 300mm in the field (middle)
  ✔ Stagger Joints – Alternate board seams for strength.
  ✔ Butt Joints Tight – Minimize gaps for easier taping.

Pro Tip:

• Pre-drill screws to avoid "chewing" the metal studs.

Timber Battens

An alternative to metal framing, often used in refurbishments.

1. Fixing Plasterboard to Timber Frameworks
✔ Batten Spacing – Typically 400-600mm centers (closer for thicker boards).
✔ Secure Battens – Use 50mm screws or nails into solid masonry or timber.
✔ Check for Level – Shim uneven walls before fixing boards.
✔ Screw/Nail Placement –

• 15mm from edges to avoid blowouts.

• 200-250mm spacing for 12.5mm board.

Pro Tip:

• Treat timber battens in damp areas to prevent rot.

Comparison of Fixing Methods

Final Notes:

• Always back-block joints in metal framing for better screw grip.

• For fire-rated walls, follow manufacturer spacing rules for screws/adhesive.